SF Flotation Machine
Copper, Lead-Zinc & Graphite Circuits
Factory-direct SF flotation cells for copper sulfide, lead-zinc, graphite, fluorite, and gold-bearing sulfide recovery. The self-aspirating SF series covers 7 cell sizes from 0.37 to 20 m³ for rougher, cleaner, and scavenger banks without a separate air blower.
- Copper sulfide, lead-zinc, graphite, and fluorite duties
- Rougher, cleaner, and scavenger bank planning
- Popular production sizes: SF-8, SF-16, and SF-20
7
Cell Sizes
20 m³
Largest Cell
Cu / Pb-Zn
Common Duties
Need SF-8 or SF-16 layout support?
After duty confirmation, we provide outline drawing guidance, motor layout references, and cell-bank arrangement suggestions for procurement and civil planning.
How Froth Flotation Works
Flotation exploits surface chemistry: valuable mineral particles are made hydrophobic by chemical reagents, then selectively attach to air bubbles and float to the surface as a mineralised froth — while gangue minerals stay wetted and sink.
01
Grind & Condition
Ore is ground to liberation size (typically 75–150 µm) in a ball mill. Reagents (collector, frother, pH modifier) are added and mixed with the slurry in conditioning tanks to coat mineral surfaces.
02
Aerate
Slurry enters the flotation cell. The self-aspirating impeller draws air down the hollow shaft and disperses it into fine bubbles (0.5–2 mm). The stator breaks air pockets into uniform bubble size.
03
Attach & Rise
Hydrophobic (collector-coated) mineral particles collide with air bubbles and attach. The bubble-particle aggregates rise buoyantly to the surface, forming a stable mineralised froth layer.
04
Collect Froth
Mechanical scrapers continuously push the mineralised froth over the overflow weir into the concentrate launder. Gangue slurry exits from the cell bottom as tailings.
Flotation Reagent Types
Make the target mineral surface hydrophobic so air bubbles attach. Common types: xanthates (potassium amyl xanthate, PAX) for sulfides; fatty acids (oleic acid, tall oil) for fluorite, apatite; diesel for coal. Dosage: 20–200 g/t.
Stabilise air bubbles so the froth layer persists long enough to overflow the weir. Common types: MIBC (methyl isobutyl carbinol), pine oil, polypropylene glycols. Dosage: 20–100 g/t.
Prevent unwanted gangue or minerals from floating. ZnSO₄ + NaCN depresses zinc and pyrite; lime raises pH to depress pyrite; sodium silicate disperses silicates. Dosage varies widely.
Restore hydrophobicity to minerals temporarily depressed or naturally difficult to float. CuSO₄ activates sphalerite (ZnS). Na₂S activates oxidised copper and lead minerals.
Adjust pulp pH to control selectivity. Lime (CaO) for alkaline conditions (pH 8–12, most sulfide circuits). H₂SO₄ for acidic conditions (pH 4–6, some oxide circuits). pH is the single most critical control variable.
Flotation Circuit Stages
A complete flotation plant uses multiple stages in series, each with a bank of SF cells. Grade and recovery are balanced across the circuit.
First-pass flotation recovers the bulk of valuable mineral into a low-grade rougher concentrate (typically 2–8× feed grade). Recovery is the priority — high reagent dosage, longer residence time. Rougher tails go to scavenger.
Processes rougher tailings to capture remaining mineral value. Low reagent dosage, coarse froth setting. Scavenger concentrate (low grade) is recycled back to the rougher or cleaner feed.
Upgrades rougher concentrate to final saleable grade. Less residence time needed, fine froth, low collector. Multiple cleaner stages (2–3 stages) progressively raise grade. Cleaner tails return to rougher.
Optional additional cleaning stage for high-grade targets (e.g., >25% Cu). Each re-cleaner stage increases final grade but reduces overall recovery — circuit designer must balance both.
Typical minimum circuit: Rougher + Cleaner + Scavenger
For most sulfide ores, a 3-stage circuit (rougher, one cleaner, one scavenger) delivers 85–95% metal recovery at saleable concentrate grade. Complex ores with fine-grained mineralogy or high gangue penalty elements may require additional cleaner stages or combined processes (e.g., flotation + leach).
SF Series — Model Specifications
7 cell sizes from 0.37 m³ (lab / pilot) to 20 m³ (large-scale production). All models are self-aspirating — no external air blower required.
| Model | Cell Volume | Capacity | Impeller Dia. | Motor Power | Weight | Get Quote |
|---|---|---|---|---|---|---|
| SF-0.37 | 0.37 m³ | 0.2–0.4 m³/min | 300 mm | 1.5 kW | 0.45 t | Quote |
| SF-1.2 | 1.2 m³ | 0.6–1.6 m³/min | 450 mm | 5.5 kW | 1.8 t | Quote |
| SF-2.8 | 2.8 m³ | 1.5–3.5 m³/min | 550 mm | 11 kW | 3.2 t | Quote |
| SF-4 | 4 m³ | 2–4 m³/min | 650 mm | 15 kW | 4.1 t | Quote |
| SF-8 | 8 m³ | 4–8 m³/min | 760 mm | 30 kW | 7.5 t | Quote |
| SF-16 | 16 m³ | 5–16 m³/min | 850 mm | 45 kW | 12 t | Quote |
| SF-20 | 20 m³ | 10–12 m³/min | 850 mm | 45 kW | 14 t | Quote |
* Capacity in m³/min refers to pulp flow rate through the cell bank, not ore tonnage. Tonnage depends on ore specific gravity and % solids. Contact us to convert your t/h requirement to required cell volume.
Processable Minerals
The strongest commercial fit for SF cells is copper sulfide, lead-zinc, graphite, fluorite, and similar flotation duties where buyers need stable bank sizing and predictable air distribution.
Copper (Sulfide)
CuFeS₂ / Cu₂S
Primary flotation with xanthate collector. Typical concentrate: 20–30% Cu. One of the most common SF machine applications.
Lead & Zinc
PbS / ZnS
Sequential differential flotation — float lead first with low pH, then activate zinc with CuSO₄. SF machines handle both stages.
Gold (Sulfide-hosted)
Au in pyrite / arsenopyrite
Float the sulfide carrier mineral with xanthate; gold follows. Concentrate then goes to CIL or smelting.
Molybdenum
MoS₂
High-grade MoS₂ concentrate (45–52% Mo) achievable. Often combined after bulk Cu-Mo float then selective depression.
Fluorite
CaF₂
Non-sulfide flotation with fatty acid collector. Produces acid-grade CaF₂ (97%+) for HF manufacturing.
Graphite
C (crystalline)
Natural graphite is naturally hydrophobic — light collector dosage only. SF machines produce flake graphite concentrates.
Coal / Fine Coal
—
De-ashing of fine coal (<0.5 mm) where gravity separation is ineffective. Diesel oil as collector, MIBC as frother.
Nickel & Cobalt
NiS / CoAsS
Pentlandite and cobaltite float with xanthate. Circuits typically include magnetic separation to remove pyrrhotite.
Main Components
Six key components — each one is an independent operating variable. Understanding all six lets you systematically tune the circuit for maximum grade and recovery.
Cell Tank
Forward-inclined rectangular trough that minimises dead corners and accelerates froth movement toward the overflow weir. Tank geometry directly affects residence time and froth recovery.
Impeller
Double-sided backward-rake impeller blades create dual circulation: upper zone aerates the pulp; lower zone resuspends settled coarse particles. Low rotation speed (200–400 RPM) reduces reagent shear and wear.
Stator / Disperser
Stationary cage surrounding the impeller that breaks large air pockets into fine bubbles (0.5–2 mm). Bubble size is the most important factor for mineral recovery — smaller bubbles have more surface area per unit volume.
Air Intake Pipe
In self-aspirating SF design, impeller rotation creates vacuum that pulls ambient air down the hollow shaft without a blower. Air flow rate is controlled by the intake valve — a critical operating variable.
Froth Weir & Scraper
Overflow weir height sets the froth depth. Mechanical scrapers (paddles) push froth over the weir into the concentrate launder continuously. Scraper speed affects froth retention time and concentrate grade.
Level Control Valve
Controls pulp level inside the cell to maintain consistent froth depth. In a multi-cell bank, the level in each cell is set independently to optimise recovery progression from rougher to scavenger.
How to Size Your Flotation Circuit
Flotation circuit design is more complex than crusher selection — it requires knowledge of your ore's mineralogy, grind size, and required concentrate grade. Our metallurgical team can help.
01
Determine Required Total Cell Volume
Total cell volume (m³) = Feed flow rate (m³/min) × Required residence time (min). Typical residence time: rougher 8–15 min, cleaner 4–8 min, scavenger 8–12 min. This gives total bank volume — divide by individual cell size to get number of cells needed.
02
Select Cell Size
Larger cells (SF-8, SF-16, SF-20) reduce capital cost and floor space per m³ of volume. Smaller cells (SF-0.37, SF-1.2) offer finer control in lab and pilot circuits, or when handling low-volume high-value streams.
03
Plan Rougher–Cleaner–Scavenger Stages
A minimum circuit has rougher + cleaner + scavenger. For challenging ores (low grade, fine-grained, complex mineralogy) add re-cleaner stages. Each stage typically uses 3–8 cells in a bank.
04
Confirm Reagent Compatibility
SF machines work with all standard reagent suites. If your circuit uses cyanide (for gold), ensure materials of construction (shaft seals, rubber linings) are cyanide-resistant. Confirm with our applications team.
Need a full flotation circuit design?
Tell us: ore type, feed grade (%), target concentrate grade, daily throughput (t/d), and grind size target. We'll propose a complete rougher–cleaner–scavenger circuit with cell count, cell size, and reagent recommendations.
Maintenance Schedule
Flotation cells are mechanically simple. Most performance issues are process-related (reagent dosage, pH, grind size) rather than mechanical — operators should learn to read the froth.
Every Shift
- Monitor froth texture — dry, sandy froth means insufficient air or reagent; wet, watery froth means too much frother
- Check pulp level in each cell; adjust level valve if froth depth has shifted
- Inspect froth scraper paddles for wear or breakage — damaged scrapers cause concentrate loss
- Verify reagent dosing pumps are running at set rates; check feeder pipes are not blocked
Weekly
- Inspect impeller for wear — check blade leading edge thickness; replace when worn to 50% of original
- Check stator bars for wear; stator wear increases bubble size and reduces recovery
- Lubricate impeller shaft bearing per schedule
- Clean froth launder of settled concentrate build-up
Monthly
- Replace impeller and stator as a matched pair — mismatched wear causes uneven aeration
- Drain and inspect cell for rubber lining condition; patch or replace if torn
- Check all reagent addition points for correct location and flow pattern
- Calibrate level control valves — drift causes froth depth inconsistency across the bank
Why Choose MarsCrusher SF Series
Self-aspirating impeller — no external air blower required
Double-sided backward impeller blades create dual slurry circulation to prevent sedimentation
Forward-inclined tank minimises dead zones for fast froth removal
Low impeller speed extends blow bar and impeller wear life
Large air intake volume with low unit energy consumption
Can be configured as suction cell or direct-flow cell in series circuits
Flotation Machine FAQ
Short answers to common procurement questions before requesting quotation.
How many flotation cells do I need for a copper or lead-zinc plant?
Cell count comes from feed flow and required residence time across rougher, cleaner, and scavenger stages. For copper or lead-zinc circuits, sizing should ideally be checked against metallurgical test data before final model selection.
Does SF flotation machine need an external blower?
Standard SF design is self-aspirating and usually does not need an external air blower, which simplifies installation and operation.
What process variables most affect recovery in an SF flotation circuit?
The highest-impact variables are grind size, reagent regime, pH control, and froth depth. Mechanical condition matters, but process control usually dominates results.
Can SF flotation machine be used for copper, lead-zinc, graphite, and gold circuits?
Yes. SF cells are widely used in copper sulfide, lead-zinc, graphite, fluorite, and gold-associated sulfide circuits when process design, residence time, and reagent suite are properly configured.
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